Genetically engineered identical twins Kyle and Connor McAdams were born two years apart. Connor was born first, and he was the best at everything: valedictorian, star quarterback... everything. Kyle never thought he'd be able to live up to his twin, so he didn't even try. But when Connor suddenly drops dead of a heart attack, Kyle learns of other genetically modified kids who've also died on their eighteenth birthdays. Now Kyle is motivated-- to save his own life.